1. Technical Field
The present invention relates generally to air bearings, and more particularly, to an air bearing including a unitary housing for supporting a shaft using a gas.
2. Related Art
FIG. 1 illustrates a conventional air bearing 8 including a housing 10 for supporting a shaft 12. Housing 10 includes an outer body 14 and an insert 16. Pressurized gas is delivered to support shaft 12 via a passage 18 that extends though body 14 and insert 16. Conventional air bearings 8 suffer from a number of disadvantages. First, conventional air bearings use inserts 16 that do not allow touching of shaft 12 to the insert. For example, where insert 16 is made of a soft material such as bronze, touching of shaft 12 to insert 16 may cause material transfer to shaft 12 with the bronze or debris to be released within the system, and/or galling of shaft 12. Second, manufacturing of conventional air bearings requires assembly of multiple parts of housing 10, i.e., outer body 14 and insert 16, which adds complexity to the process. In particular, inserting of insert 16 into outer body 14 requires interference conditions, which leads to yield loss issues where insert 16 is made of a brittle material such as graphite. Third, insert 16 may leak to the extent that collapse of insert 16 under normal operating pressures can occur. For example, graphite inserts 16 tend to collapse when the pressure is turned on.
In view of the foregoing, there is a need in the art for an air bearing that does no suffer from the problems of the related art.